1. Field of the Invention
The present invention relates to a skin patch comprising a matrix which adheres to the skin and contains at least one active cosmetic substance and a combination with a skin wrap to produce an effective compression for treating cellulite and/or stretch marks of the skin, such as, e.g., striae.
2. Discussion of Background Information
Cellulite (medical term: dermopanniculosis) is not a disease, but a cosmetic problem.
The reasons for cellulite lie above all in the special structure of female skin and in the reaction to female hormones. Fat cells are stored in the hypodermis. Their quantity is already determined in infancy and cannot be influenced by diet or sport. The fatty acids from diet are converted into fats in the fat cells and are stored in the connective tissue in a nodular manner. If these fats are not broken down for a long period (e.g., sport) and if the body in addition is overfed, the cells can expand by a multiple of their size. The enlarged cells then push through the connective tissue and the feared orange peel skin occurs, also known as cellulite.
The further consequences in old age are small varicose dilatations of the cutaneous veins, varicose veins, thrombosis and leg complaints. The thighs often also store superfluous fat that is absorbed through the diet. The unsightly thickening at the sides of the thighs, also known as saddle bags, combined with cellulite, is often a great strain on those affected.
The so-called body wrap principle is known for treating cellulite. A special body wrap gel is applied to the problem areas thereby and they are subsequently wrapped in a wrapping foil. A heat effect is thereby produced and a purification of the tissue takes place through the active substances of the body wrap gel and the heat development.
Through the application of the gel and the wrap shorts, the lymphatic circulation is to be stimulated and through the heat generation toxins, fats and wastes are to be removed from the body. in this manner Striae are also reduced, cellulite is reduced and the so-called saddle bags are also reduced after only a few treatments.
Anti-cellulite plasters (e.g., “Perfect Slim Cellulite Patch” from L'Oréal) are also known, the components of which, such as seaweed or caffeine, promote the smoothing of the unsightly dimples. The beauty plasters in particular make the application easier for women who are tired of having to apply cream all the time. Thus areas particularly affected can be treated in a targeted manner. The advantage of a patch of this type lies in the continuous dispensing of active substances over eight hours by the plaster. Moreover, these can also be used at night.
The preparation CREALITE by Creaderm uses nanotechnology against cellulite for the first time. Caffeine is transported through the skin into the subcutaneous fatty tissue with liposomes.
CREALITE contains large-dose caffeine (2%) in a specially suitable carrier. Caffeine withdraws water from the cells and in addition inhibits the enzyme cyclic M3′,5′-nucleotide phosphodiesterase, through which a weight loss is to be achieved. The fat cells which are very much enlarged with cellulite are to be made smaller thereby and the skin is to appear tauter and smoother again.
WO 05/007127, WO 04/093865, WO 04/074216 and WO 04/060268 likewise highlight numerous cosmetic active substances and treatment methods for cellulite.
EP 1181926, EP 728472 and EP 493151 likewise disclose in particular cosmetics containing caffeine for cellulite treatment.
The object of the present invention is to disclose alternatives for the treatment of cellulite.
Stretch marks in the skin after pregnancy which impair the on the aesthetic appearance are an annoying cosmetic phenomenon. So-called stretch marks are also called striae. This is not a disease, but a purely cosmetic problem.
Skin stretch marks (striae) are tears in the subcutaneous tissue. They occur on the abdomen, hips or breast. Striae are bluish red at first, then yellowish white. They have a similar appearance to scars. They occur whenever the skin is overstretched and at the same time the elasticity of the skin has decreased. A high cortisone level promotes the formation of stretch marks. This hormone allows the skin to retain more water and it reduces the elasticity of the skin.
If the skin is stretched by a pregnancy or weight gain, small tears occur in the elastic tissue. The skin becomes thinner at the affected areas and the blood vessels shine through in a bluish color. Later the areas form a scar and the marks become white. Unfortunately, they will not disappear again.
Pregnant women, people in puberty, competitive athletes, people undergoing hormone treatment and people with increased weight are the groups most affected by Striae.
During pregnancy there is a higher cortisone level in the blood. Stretch marks occur here in the skin of the abdomen in the case of many women. They are called “striae gravidarum” or pregnancy stretch marks.
Once stretch marks are present, according to the current standard of knowledge they cannot be completely reduced. A reduction and abatement up to 50% is possible. It also applies to laser treatments that they do not usually achieve the desired success.
The object of the present invention is therefore also to provide a skin patch that renders possible a treatment of the skin areas affected by striae and brings about a cosmetic improvement of these skin areas.
The skin is exposed to constantly changing environmental influences and over time is subject to a number of changes. Thus changes in the barrier properties, the degree of skin wrinkles and elasticity, pigmentation and in particular, due to exogenic influences, also inflammatory reactions and, e.g., also after-reactions of the skin to the impact of UV radiation result.
The barrier effect of the skin can be quantified via the determination of the transepidermal water loss (TEWL). This is the evaporation of water from the interior of the body without including the loss of water during sweating. The determination of the TEWL value has proven to be extraordinarily informative and can be used for the diagnosis of cracked or chapped skin, to determine the tolerance of surfactants with different chemical structures and the like.
The proportion of water in the top dermal layer is very important for the beauty and well-groomed appearance of the skin. It can be favorably influenced to a limited extent by introducing moisture regulators.
Cosmetic skin care means primarily strengthening or rebuilding the natural function of the skin as a barrier against environmental influences, e.g., dirt, chemicals, microorganisms, and against the loss of endogenous substances, e.g., water, natural fats, electrolytes.
If this function is impaired, an intensified absorption of toxic or allergenic substances or an attack by microorganisms leading to toxic or allergic skin reactions can occur.
The aim of skin care is furthermore to compensate for the loss by the skin of lipids and water caused by daily washing. This is particularly important if the natural regenerative ability is insufficient. Moreover, skin care products should protect against environmental influences, in particular sun and wind, and delay skin aging.
Chronological skin aging is caused, e.g., by endogenous, genetically determined factors. The following structural damage and functional disorders, which can also come under the term “senile xerosis”, can occur, e.g., in the epidermis and the dermis due to aging:    (a) dryness, roughness and the formation of small lines due to dryness,    (b) itching and    (c) reduced regreasing by sebaceous glands (e.g., after washing).
Exogenous factors, such as UV light and chemical noxae, can have a cumulative effect. In the epidermis and dermis, in particular due to exogenic factors, e.g., the following structural damage and functional disorders occur in the skin:    (d) increased susceptibility to mechanical stress (e.g., cracking).
Products for the care of sensitive, itchy or dry skin or products for the treatment or prophylaxis of DNS damage are known per se. However, their effectiveness is limited.
It is therefore the object of the present invention to provide in particular cosmetic skin patches that offer an additional effective protection from harmful oxidation processes in the skin as well as offering additional protection from or helping to reduce dryness, roughness and the formation of wrinkles due to dryness, itching, reduced regreasing by sebaceous glands, e.g., after washing, and increased susceptibility to mechanical stress, e.g., cracking.
Preparations are known in the prior art which, applied to the skin or the mucous membranes, are to have a moisturizing and cooling effect. In the literature for example ionic compounds, in particular ammonium salts, are described as cooling agents. Isopropanol gels with added camphor and menthol are also widely used as cooling preparations, and essential oils, primarily camphor and menthol, but also derivatives thereof, e.g., menthyl lactate or menthyl-3-hydroxybutyrate, are generally frequently incorporated into cooling compositions.
Menthol, camphor and derivatives thereof, as well as other essential oils, lower the stimulus threshold of neuronal cold receptors and thus produce a cold sensation. However, they often cause an increase in blood supply at the same time, which in contrast generates a sensation of heat. The application of these substances, especially on irritated skin, is at any rate problematic. Moreover, many of these compounds have poor water solubility. Their use is consequently limited to a few cosmetics and dermatics.
The object of the present invention is therefore also to provide a skin patch that does not have the listed disadvantages or has a reduced level thereof while moisturizing, cooling and/or increasing blood supply.
In the case of plaster systems that contain active substances and remain on the skin for a long time, a main focus is naturally on the skin tolerance of the adhesive matrix. It is expected to be not irritating to the skin, to have good adhesion, in particular over a longer application period, and to guarantee a painless removal of the plaster or pad without leaving a residue. This expectation is not met by many known adhesive substances, such as rubber, silicone, resins or styrene hydrocarbons, which are used in particular to improve the adhesive properties. These known adhesive substances often lead to the occurence of skin irritations, allergies, macerations and/or a painful removal of the plaster from the skin.
The therapeutic mechanism of plasters or cosmetic matrices for administering cosmetic substances into and onto the skin are subject to an analogous functional principle such as Transdermal Therapeutic Systems (TTS). The terms plaster, cosmetic/dermatological matrices and cosmetic/dermatological pads are used synonymously below.
Transdermal Therapeutic Systems for dispensing active substances into or through the skin have been known for a long time and represent plaster-type systems, in particular delivering medicinal agents
The topical application of cosmetic and dermatological active substances via plaster systems or cosmetic matrices offers two main advantages:                firstly, this form of administration produces first-order release kinetics of the active substance, thereby allowing a constant level of the active substance to be maintained in the skin over a long period of time.        secondly, an additional intensive care of the skin can be effected via suitable systems.        
The time-dependent release of the cosmetic active substance from a TTS occurs depending on its TTS/skin distribution coefficient and its diffusion in the region of the TTS and the skin.
Both factors are determined by the composition of the matrix, thereby allowing the amount released per time unit and the duration of effectiveness to be directly influenced. Usually hydrocolloids, solubilizers and enhancers are used, allowing an improved solubility and diffusion as well as a faster transfer of the substance from TTS into the skin.
Ideally, first-order release kinetics are achieved, allowing the release of equal quantities per time unit.
One embodiment of transdermal systems of this type which has been well described in the technical literature is that of matrix systems or monolithic systems in which the active cosmetic agent is incorporated directly into the pressure-sensitive adhesive. In the ready-to-apply product a pressure-sensitive adhesive matrix of this kind, comprising the active substance, is equipped on one side with a backing, which is impermeable for the active substance, while on the opposite side there is a backing film equipped with a release layer, which is removed prior to application to the skin (kleben&dichten, No. 42, 1992, pp. 26 to 30).
The aforementioned properties of a TTS avoid the need for frequently repeated application and avoid burdening the skin with high concentrations of active substances, and so reduce irritation to the skin, which is unavoidable in the event of repeated administration of liquid and semisolid administration forms.
In summary, the advantages of the TTS lie in a distinctly improved compliance on the part of users, which is attributable to the simple and rapid administration and to the long-lasting efficacy of transdermal therapeutic systems.
One basic requirement of a TTS is effective adhesion to skin, which must be maintained over the entire period of the intended dosing of the active substance, and another is the ability for the TTS to be removed without leaving any residue. Painful redetachment of the active substance patch after a prolonged period of wear is a frequent observation. Apart from adhesives which are coated in solution onto the backing, the adhesives used also include solvent-free systems, such as hot-melt adhesives. A feature of these adhesives is that in the course of their coating it is possible to forego the use of organic solvent and dispersion media. Hot-melt adhesives are converted to a liquid form by heating and are applied thus as a melt to the respective patch backing. Apart from technical aspects, such as solvent processing, plant design with anti-explosion measures, and environmental protection strictures, medical reasons also play a part in the choice of solvent-free adhesives. Transdermal therapeutic systems are generally applied to healthy, intact skin.
Self-adhesive matrix systems for administering active cosmetic substances are among traditional applications in Asia, particularly in Japan, and are defined in the Japanese pharmacopoeia under the term “cataplasm.” Cataplasms, accordingly, are commonly prepared by mixing glycerin, water or other suitable liquids with finely pulverized active substances, with the addition of essential oils.
Glycerin functions here as a humectant, in order to prevent the cataplasms from drying out prematurely in use.
Whereas in the traditional Asian preparations natural thickeners such as alumina, etc., are employed, recent decades have seen the use, more and more, of modern synthetic raw materials, such as polyacrylic acid as a gel former, for example, for their production. This allows the cataplasms, which are commonly pasty, to be produced as hydrogel matrices having improved attractiveness and user-friendliness. EP 1 136 057 describes an aqueous gel system for cosmetic use without backing or liner, with a light transmittance of min. 70%.
EP 0 507 160 describes cataplasms containing lidocaine.
A disadvantage of the cataplasms described is that the production of the base matrices requires many different individual components such as gel formers, thickeners, plasticizers, humectants, stabilizers, emulsifiers, pH regulators, antioxidants, etc., and possibly also solubilizers and penetration enhancers in the case of active substance cataplasms. Since the adhesive performance and consistency of such a matrix is a function of the interaction of all of the individual components, targeted product development/optimization with regard to these fundamental product requirements is, correspondingly, time-consuming and difficult.
The production of polymer matrices, especially gel matrices, from polyacrylates has likewise been known for many years and is described for example in EP 0 507 160, JP 11-228340 and JP 04178323. Gel matrices are used, among other things, as an adhesive base and as an active substance reservoir in transdermal systems. Such systems have an adequate bond strength, especially to moist skin (buccal patches), but because of inadequate cohesiveness cannot be removed again completely when required.
In order to form a gel with a defined structure it is necessary for polyacrylic acid to be cross-linked. The nature of the cross-linker makes a critical contribution to the structure of the resultant gel. The customary cross-linking agents may be metal ions (e.g.: AI3+ ions), or organic compounds. Cross-linking with aluminum salts proceeds via the coordination of the oxygen functions of the polyacrylic acid to the AI3+ ions. A very close-meshed gel with high viscosity is formed, the viscosity of the gel being controllable only via the amount of cross-linker (Handbook of Pressure Sensitive Adhesive Technology, page 458 if, 1999).
JP 11-228340 discloses polyacrylic acid-based gels which utilize AI3+ compounds as cross-linkers. The use of the mandatory aluminum compound as a cross-linking agent is limited, since otherwise the physical properties of the gel are impaired. If the proportion of aluminum cross-linker is too high the gel becomes too hard.
Further examples of cross-linking with polyvalent metal ions are known from the literature, e.g., U.S. Pat. No. 3,900,610 (zinc salts), U.S. Pat. Nos. 3,770,780 or 3,790,533 (titanium compounds). Ionic cross-linking with metal ions leads to hard, viscous polymer gels with low tack (Handbook of Pressure Sensitive Adhesive Technology, page 458 ff, 1999).
EP 303445 discloses a patch with a monolithic gel matrix based on water-soluble polymers. Mandatory constituents are clebopride or a pharmaceutically acceptable salt thereof as active substance, water, water absorbers, and water-soluble polymers. As water-soluble polymers one skilled in the art is able to select from a range of known polymers such as polyvinyl alcohol, gelatin, polyacrylic acid, sodium polyacrylates, methylcellulose, carboxymethylcellulose, polyvinylpyrrolidone, rubber and other cross-linkable polymers and also mixtures thereof.
EP 976382 describes a patch comprising a matrix composed of a system which is hydrophilically gelling in aqueous phase and which is formed from gelan gum and at least one further hydrocolloid. Gelan gum is claimed mandatorily. Gelan gum is understood by one skilled in the art, as defined by technical dictionaries, to comprise hydrocolloids obtained from the following marine plants: Agardhiella tenera, Furcellaria fastigiata, Hypnea cervicornis, musciformis, spicifera, Suhria vitata. Nor is there any mention of the essential aspects of self-adhesive properties, the adjustability of bond strength and elasticity of the resultant matrices.
A further problem associated with the cross-linking of polyacrylic acid to form a self-adhesive matrix or gel is that a matrix once produced, having defined physical properties, viscosity, tack, etc., must have the same defined properties in a later production process. This reproducibility is difficult if not impossible to realize with the cross-linking technologies that are currently known.
It is also known that the adhesive composition of the plaster can be employed as the matrix comprising the active substance. In addition to self-adhesive compositions applied from solution, hot-melt self-adhesive compositions have also been proposed for this purpose, as for example in EP 0 663 431 A, EP 0 452, 034 A, EP 0 305 757 A, DE-A 43 10 012, DE-A 42 22 334 and DE-C 42 24 325. The active substances listed in these documents, if named at all, are systemic ones.
As examples of active substance plasters, mention may be made of the active substance plasters which aid the circulation, belonging to the group of locally active therapeutic systems. The use of such plasters is indicated for the treatment of rheumatic complaints, sciatica, lumbago, stiff neck, shoulder/arm pain and muscular strains and sprains, muscular aching, or muscle, joint and nerve pain in the region of the locomotor system.
Capsaicin and nonivamide are known active substances in such locally acting plasters that aid the circulation. Because of their use on the locomotor system they are in general required to adhere strongly. Usually, the plasters are coated over their whole area with a resin-rubber adhesive composition which comprises the active substance.
However, plasters of this kind, which usually have to be applied over a relatively large area, in some cases exhibit mechanical skin irritations after removal in the case of sensitive patients. After a prolonged period of application, their removal is to some extent painful.
A further disadvantage of the known thermally active plasters with an adhesive composition based on natural rubber which is applied in the form of a solution with organic solvents to the plaster backing is the comparatively low rate of release of the active substance.
The abovementioned disadvantages, and further disadvantages, apply also to active substance plasters comprising substances other than those mentioned.
For example, WO 94/02123 describes an active substance plaster based on pressure-sensitive hot-melt adhesive compositions and comprising low-melting and/or readily volatile active substances in a concentration of from 2.5 to 25% by weight.
Tapes or wound dressings can be fixed to joints or to the thigh only unsatisfactorily due to the mechanical stress. A frequent change of dressing is also customary in order to provide suitable active substances to the area to be treated on or around the joint.
In order to master the problem, plasters with substantial adhesion, shorts or stocking-like bandages are provided.
The object of the present invention is therefore also to provide an improvement in application for the care of the skin with skin patches. In particular it is an object of the present invention to provide a cellulite treatment set that is simple to use, also applicable for individual circumstances, sizes, areas of skin, and has no disadvantages regarding conventional cellulite treatments.
These objects are attained through a skin patch according to claim 1. Preferred embodiments of the patch are disclosed in the subordinate claims. Moreover, the invention also covers the use thereof. Furthermore, the objects are attained through a care set, comprising a skin patch and a wrapping.
It was surprising, and extremely astonishing to one skilled in the art, that a skin patch comprising                a matrix adhering to human skin,        at least one cosmetic active substance, whereby the active substance is contained in the matrix,attains the stated object.        